In the conventional modulation schemes applied in standards such as LTE (Long Term Evolution)/LTE-A (Advanced), the symbol intervals of symbols modulated in accordance with PSK/QAM or the like are set in accordance with the Nyquist criterion such that temporally continuous symbols do not interfere with each other (i.e., no inter-symbol interference occurs). This allows a reception apparatus side to demodulate and decode reception signals with no special signal processing but attendant processing such as orthogonal frequency-division multiplexing (OFDM) or multiple-input and multiple-output (MIMO). However, from the perspective of frequency use efficiency, it is difficult to narrow the symbol intervals of the modulated symbols beyond conditions of the symbol intervals, so that the upper limit is defined in accordance with the given frequency bandwidth, the number of MIMO antennas, and the like. It is considered to extend the frequency band of the communication system from the existing microwave band to the submillimeter-wave band, the millimeter-wave band, or the like, which is higher frequency. However, the limit will be reached some day because of limited frequency band resources. In addition, MIMO also has a physical restriction as to the installation of antennas in an apparatus, so that this will also reach the limit.
Under such circumstances, the technology referred to as faster-than-Nyquist (FTN) has attracted attention. For example, Patent Literature 1 discloses FTN. FTN is a modulation scheme and a transmission scheme which narrow the symbol intervals of modulated symbols beyond the above-described conditions of the symbol intervals to attempt to improve frequency use efficiency. Although inter-symbol interference occurs between temporally continuous symbols in the process of modulation, and a reception apparatus side requires special signal processing to receive FTN signals, such a configuration makes it possible to improve frequency use efficiency in accordance with the way to narrow symbol intervals.